revlog: introduce a mandatory `_writing` context to update revlog content Before this change, various revlog methods where managing the opening and closing of the revlog files manually and passing the file descriptor alors the call path. To simplify the tracking of the write operation by a future docket, we need something more organised. As a result, we introduce a `revlog._writing` context manager that will wrap each revlog update operation. The file descriptor are kept in the existing `revlog._writinghandles` parameter that was already used by the `addgroup` logic. All this change is internal to the revlog only, the "public" interface is not affected. The `addrevision` and `addgroup` logic are still responsible for setup up this context. However this new context give us multiple benefits: * all writer use a same, unified, logic, * this context is programmatically enforced, * each write "session" as a clearly identified start and end. The post-pull sidedata update logic is still doing writing by end and will be adjusted in a later changesets. This change affect the concurrency checker test, because register the state of the file in the transaction sooner in `addrevision` (about as early as what `addgroup` would do), so the abort is rollbacking the other commit. I don't want to weaken the current main logic. Differential Revision: https://phab.mercurial-scm.org/D10605

revlog: preindent some code in _enforceinlinesize Indenting this beforehand will make a future changeset much simpler. Differential Revision: https://phab.mercurial-scm.org/D10604

revlog: preindent some code in addgroup Indenting this beforehand will make a future changeset much simpler. Differential Revision: https://phab.mercurial-scm.org/D10603

pyoxidizer: use Python 3.9 (BC) Newer versions of PyOxidizer use Python 3.9 by default. We previously pinned the version to 3.8 to facilitate porting to a new PyOxidizer version and diffing results. Now that the porting work is complete, let's bump Python to Python 3.9. This will effectively change our Windows Inno and WiX Python 3 installers from Python 3.8 to 3.9. .. bc:: Windows .msi and .exe installers now use Python 3.9 instead of Python 3.8. Differential Revision: https://phab.mercurial-scm.org/D10689

packaging: use PyOxidizer for producing WiX MSI installer We recently taught our in-tree PyOxidizer configuration file to produce MSI installers with WiX using PyOxidizer's built-in support for doing so. This commit changes our WiX + PyOxidizer installer generation code to use this functionality. After this change, all the Python packaging code is doing is the following: * Building HTML documentation * Making gettext available to the build process. * Munging CLI arguments to variables for the `pyoxidizer` execution. * Invoking `pyoxidizer build`. * Copying the produced `.msi` to the `dist/` directory. Applying this stack on stable and rebuilding the 5.8 MSI installer produced the following differences from the official 5.8 installer: * .exe and .pyd files aren't byte identical (this is expected). * Various .dist-info/ directories have different names due to older versions of PyOxidizer being buggy and not properly normalizing package names. (The new behavior is correct.) * Various *.dist-info/RECORD files are different due to content divergence of files (this is expected). * The python38.dll differs due to newer PyOxidizer shipping a newer version of Python 3.8. * We now ship python3.dll because PyOxidizer now includes this file by default. * The vcruntime140.dll differs because newer PyOxidizer installs a newer version. We also now ship a vcruntime140_1.dll because newer versions of the redistributable ship 2 files now. The WiX GUIDs and IDs of installed files have likely changed as a result of PyOxidizer's different mechanism for generating those identifiers. This means that an upgrade install of the MSI will replace files instead of doing an incremental update. This is likely harmless and we've incurred this kind of breakage before. As far as I can tell, the new PyOxidizer-built MSI is functionally equivalent to the old method. Once we drop support for Python 2.7 MSI installers, we can delete the WiX code from the repository. This commit temporarily drops support for extra `.wxs` files. We raise an exception instead of silently not using them, which I think is appropriate. We should be able to add support back in by injecting state into pyoxidizer.bzl via `--var`. I just didn't want to expend cognitive load to think about the solution as part of this series. Differential Revision: https://phab.mercurial-scm.org/D10688

packaging: extract invocation of pyoxidizer to own function I'll be refactoring how the WiX installer creation calls into pyoxidizer and will need a lower level function for facilitating that. The new `run_pyoxidizer()` builds our execution environment (with gettext available) and invokes `pyoxidizer`. Differential Revision: https://phab.mercurial-scm.org/D10687

packaging: rename run_pyoxidizer() I'm going to split this function up in a future commit and I'll want the name "run_pyoxidizer()" for a lower-level function for invoking `pyoxidizer`. Differential Revision: https://phab.mercurial-scm.org/D10686

packaging: move documentation HTML building to own function This is part of some light refactoring to enable us to use PyOxidizer for WiX MSI installer generation. Differential Revision: https://phab.mercurial-scm.org/D10685